Internal-combustion engine



Jul 14, 1925.

Filed Oct. 8, 1924 'lIIIIII/(IIII/f/ Patented July 14, 1925.

UNITED STATES v 1,546,008 PATENT OFFICE.

EVERETT R. BURTNETT, OF LOS ANGELES, CALIFORNIA, ASSIGNOR OF ONE-HALF TO HOMER A. BRUNELL, 01 L08 ANS-E1413, CALIFORNIA.

INTERNAL-COMBUSTION Enema.

Application filed Qctober 8, 1924. Serial No. 742,404.

To all whom it ma concern;

Be it known that EVERET'I R. BURTNE'IT, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

My invention relates to a two stroke cycle internal combustion engine, the principal object of my invention being to provide an engine unit comprising three cylinders, two of which function as combustion or power cylinders and the third as a gaseous fuel precompression and pumping cylinder, in which unit the design and arrangement provide, without special counterbalancing, the desired balanced rotary mass.

Further objects of my invention are to generally improve upon and simplify the construction of the existing forms of similar two stroke cycle internal combustion engine; to provide an engine in which the cylinders are formed in a V-structure with the combustion cylinders arranged in a row parallel with the axis of the crank shaft of the engine, and the pump cylinder being disposed in a plane that occupies an angle relative to the combustion cylinders and radially with respect to the axis of the crank shaft; to provide a crank shaft for the unit of three cylinders and arrange a separate connection between the three pistons within the three cylinders of the unit and three separate crank throws of said crank shaft; to arrange the cranks to which the pistons of the two combustion cylinders are connected in the same plane so that the pis tons of the two combustion cylinders, which latter have parallel axes, move simultaneously and in 'the same relation; and to provide a diametrically opposite crank to which thepiston of the pump cylinder isconnected,

the axis of said pump cylinder being radially disposed. with respect to the crank shaft and angularly disposed relative to the plane occupied by the axes of the combustion cylinders.

It is also one of the objects of my invention to arrange the pump cylinders and combustion cylinders inangular'relationto each other and to arrange-the pump cylindersbehind or to the rear of the combustion cylinders in the direction of crank shaft rotation, so that the piston .in' each pumping cylinder, which functions for pumping precompressed gaseous fuel to one pair of the combustion cylinders, will'reach top or inner' dead center at the time the istons within the corresponding pair combustion cylinders have 'moved a suflicient distance inward from outer or bottom dead center to close the ports through which the gaseous fuel is admitted into said combustion cylinder from the res ective corresponding pump cylinder. y virtue of this arrangement, there is no communication between the combustion cylinder and the corres onding or respective pumping cylinder after the piston within the latter begins its outward or suction stroke, and asa result the total volume of fresh gaseous fuel inducted or pumped into the combustion cylinders will be retained therein, thus providing a relatively high volumetric efiiciency in the transfer of the precompressed charge of fresh gaseous fuel from each pumping cylinder to the combustion cylinders that are served thereby. 7

With the foregoing and other objects in view, my invention consists in the features of construction and combination and arrang'ement of parts hereinafter more fully described and claimed, reference being bad to the accompanying drawings, in which: 7

Figure 1 is a vertical section taken lengthwise through the center of the cylinders of an engine of my improved construction;

Figure 2 is a section taken on the line 2-2 of Figure 1;

Figure 3 is a section taken on .the'line 33 of Figure 1.

Referring by numerals to the accompanying drawings, which illustrate a practical embodiment of my invention, 10 designates a crank case of suitable form, which may beconstructed in two or more parts, and arranged on the end walls thereof are bear in-gs 11 for a crank shaft 12, the latter having three cranks or'throws 13, 14 and 15.

Cranks 13 and 14 occupy the same plane and formed a pair of combustion chambers 17 and 18, the axes thereof being parallel with each other and in a plane that intersects the axis of crank shaft 12. Pistons 19' and 20 are arranged for operation, respectively, within the combustion chambers 17 and 18, and connecting piston 19 with crank 13 is a suitable connection rod 21. A similar connecting rod 22 connects piston 20 with crank 14. As a result of this arrangement, pistons 19 and 20 operate simultaneously and they always occupy the same relative positions within their respective chambers.

Arranged on the upper 'or head end of block 16 is a head block 23 and formed in the under side thereof is a shallow recess or pocket 24 that provides a common clearance compression and combustion chamber for the chambers 17 and 18. Formed in the wall of block 16 that surrounds chamber 17 is an exhaust port 25, the same being located so that it is uncovered and open only when the piston 19 within said chamber 17 is at the lower or outer end of its stroke.

Formed on or fixed to the upper portion of crank case 10 and on the opposite side of a vertical plane passing through the axis thereof, from the row of combustion c l-' inders just described, is a block 26 in which is formed a gaseous fuel precompression and pumping chamber 27, and within which operates a pumping piston 28. Piston 28 is connected to crank 15 which is between cranks 13 and 14 by a connecting rod 29,

and in order to properly counterbalance the reciprocative and rotary masses of the engine structure, the lower portion of this connecting rod is preferably increased in size so as to give it the desired counterbalancin weight.

ormed through the wall of block 10 surrounding combustion cylinder 18 is a gaseous fuel inlet port 30, the same being located so that it is uncovered and open only when piston 20 is at the lower or outer end of its stroke, and leadin from common clearance chamber 24 to t is inlet port 30 is a gaseous fuel transfer duct 31.

The axis of pumping cylinder 26 intersects the axis of the crank-shaft so that blocks-16 and 26 provide a V-structure, with block 26 behind or to the rear of block 16 in the direction of crank rotation. In other words, as the crank shaft rotates clockwise, the cranks thereof will pass beneath the combustion cylinders 16 before passing beneath the pumping cylinder 26.

,The degree of the angle between the two rows of cylinders must be such that, when piston 28 within pump cylinder 26 reaches upper or inner dead center, the pistons 19 and 20 within the combustion cylinders will have moved a suflicient distance inward from their outer or lower dead centers as to enable piston 20 to close the gaseous fuel inwhatever let port 30 that leads from the lower end of duct 31 into the combustion chamber 18. This provision effectually prevents a portion of the gaseous fuel charge that is inducted to the combustion cylinders from returning to the pump cylinder.

' Seated in head block 23, and preferably at a point above combustion chamber 18, is an ignition device 32, preferably a spark plug, and the terminals of the electrodes thereof project into common clearance chamber 24. Formed in cylinder 26 is a gaseous fuel inlet port 33, the same being positioned so that it is uncovered and open only when pumping piston 28 is at the lower or outer end of its stroke. v

' During the operation of my improved engine, as described, pumping piston 28 pumping pist-on and the power pistons movesimultaneously in opposite directions, but due to the angularity between the combustion cylinders and the pumping cylinder, the combustion pistons are moving downward and approaching their low dead center positions while pumping piston is moving upward during the latter portion of its up-- ward stroke. Piston 20 reaches low center or in a position where the transfer inlet port 30 is wholly uncovered prior to the time the pumpin piston 28 reaches high center, so that t e compressed charge of gaseous fuel will rush throu h port 30 as soon as the same is uncoveref into combustion chamber 18, and this incoming charge will rush upward through combustion chamber 18, thence through common clearance chamber 24, and thence downward through combustion chamber 17, and in so doing it will drive before it the greater portion of the residual products of combustion resulting from the previously ignited fuel charge. These residual products of combustion will be forced out through exhaust port 25, which is open while ist-on 19 is at the lower end of its stroke. hen pistons 19 and 20 have moved upward a short distance, or so that piston 20 entirely closes and cuts off the transfer inlet port 30, pum in piston 28 will have reached its upper diaa center, the position of the parts at this time beingillus ftrated in Figure 1, and during the remaining upward travel of pistons 19 and 20 the inducted charge of fresh gaseous fuel and roducts of'combustion remain in chamber 1 will be compressed within common clearance chamber 24 until at the point of highest compression or when pistons 19 and 20 pass high center the compressed fuel charge will be ignited by a spark producedbetween'the terminals of the electrodes of spark lug 32 and the rapid rise in pressure following combustion of the compressed charge will, act upon the heads of pistons 19 and 20 to drive the same downward on their.

power stroke.

As pumping piston 28 passes low or outer center, gaseous fuel inlet port 33 is uncovered, thereby admitting to the pumping chamber 24 a fresh charge of gaseous fuel which is compressed on the upward stroke of the pumping piston.

' Thus it will be seen that I have produced a relatively simple, strong, rugged and compactvinternal combustion engine that operates on the two stroke cycle principle and in which engine the operating parts are arranged and designed so as to produce withbut special counterbalancing a balancedrotary mass, consequently eliminating vibration and adding materially to the efiiciency of operation of the engine.

Obviously various minor changes in the 1 size, form and construction of myimproved internal combustion engine may .be made without departing from the spirit of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

'1. In a two stroke cycle internalcombus tion engine, a power unit comprising a pair of combustion cylinders and a pumping cylinder, the head ends of the combustion c linders being connected by a common c earance chamber, one of the combustion cylinders being provided with an exhaust port, there being a gaseous fuel transfer duct leading from the head end of the pumping cylinder to the other one of the two combustion cylinders, the pumping cylinder being provided with a gaseous fuel inlet port, a crank shaft havinguthree throws, the central one of which t ows is arranged diametrically opposite to the two end throws pistons arranged for operation within all of the cylinders, connections from the pistons in the combustion cylinders to the two end throws of the crank shaft, and a connec tion from the piston in the umping 0 linder to the central throw of t e crank shaft.

2. In a two stroke cycle internal combustion engine, a power unitcomprising' a pair of combustion cylinders and a pumping cylinder, the head ends of the combustion cylinders being connected bya common clear ancechamber, one of the combustion cylinders being provided with an exhaust port, there\ being a gaseous fuel transfer duct leading from the head end'of the pumping cylinder to inlet ports in one of the two combustion cylinders, the pumping cylinder being provided with a gaseous fuel inlet port,

a'crank shaft having three throws, the central one of which throws isarranged diametrically opposite to the two end throws, pistons arranged for operation within all of the cylinders, connections from the pistons in the combustion cylinders to the two end throws of the crank shaft, a connection from the piston in the pumping cylinder to the central throw of the crank shaft, and

said pumping cylinder and the two combustion cylinders being angular-1y disposed relative to each other so that the piston within the combustion cylinder having the gaseous fuel transfer inlet port closes the latter on its upward stroke at the time the piston in the pumping cylinder reaches the upper or inner end of its stroke.

3. In a two stroke cycle internal combustion engine, a power unit comprising a pair of combustion cylinders, the head ends of which are connected by a common clearance chamber, a pumping cylinder the axis ofoperation within t e three cylinders, a three throw crank shaft, theaxis of which is intersected by the axes of the three 0 linders,

and separate connections from the t ree pistons to the respective cranks of said three throw crank shaft.

.@-- 4i In a two stroke cycle internal combustion engine, a power unit comprising a pair of combustion cylinders and a pumping cylinder, said pumping cylinder being centered in a plane passing'centrally between the pair of combustion cylinders, the head ends of the combustion cylinders being connected by a common clearance chamber, one of the combustion cylinders being provided with an exhaust port, there being a aseous fuel transfer duct-leading from the bad end of the pumg ngcylinder to the other one of the two com ustion cylinders, the pumping cylinder being provided with-a gaseous fuel mlet port, a crank shaft having three throws,

the central one of which throws is arranged,

diametrically opposite to the two end throws, pistons arranged for operation within all of the cylinders, connections from the pistons in thecombustion c linders to the two end throws of the era shaft, a connection from the piston in the pumping cylinder to the central throw of the crank shaft,

'said pump cylinder being disposed at an 7 angle relative to the pair of combustion cylln ers and the degree of angularity between the axes of the combustion cylinders and the pump cylinder being equal to the number of degrees of crank shaft rotation required to cause the piston of the cylinder to which the fuel charge is inducted from the pump cylinder, to move a suflicient distance past crank and dead center to close the port through which said fuel'charge is inducted as the piston of the pump cylinder reaches top or inner dead center.

5. In a two stroke cycle internal combustion engine, a power unit comprising a pair of combustion cylinders, the head ends of which are connected by a common clearance chamber, a pumping cylinder the axis of which occupies an angular plane relative to the plane occupied by the axes of the'combustion cylinders, said pumping cylinder being centered in a circumferential plane between the axes of the combustion cylinders, one of the combustion cylinders being provided with a gaseous fuel inlet port, the other combustion cylinder being provided with an exhaust port, a compressed gaseous fuel transfer duct leading from the head end of the pumping cylinder to the inlet port in the combustion cyhnder, the pumping cyl inder being rovided with a gaseous fuel inlet port, pistons arranged for operation within the three cylinders, a three throw crank shaft, the axis of which is intersected by the axes of the three cylinders, separate connections from the three pistons to the respective cranks of said three throw crank shaft, the angularity between the plane ocpump cylinder being centered in a plane passing between the pair of combustion cy'linders and being connected to--the crank throw arm, between two crank throws to which the pair of connections from the combustion cylinder pistons are connected.

In testimony whereof I ailix my signature.

EVERETT R. BURTNETT. 

